1. Field of the Invention
The present invention relates to a nitride semiconductor laser and an epitaxial substrate for the nitride semiconductor laser.
2. Related Background Art
Patent Literature 1 discloses a nitride semiconductor laser device. The nitride semiconductor laser device is improved in crystallinity of guiding layers, an active layer, etc. and is configured to emit laser light of a long-wavelength. Patent Literature 2 discloses an oxide semiconductor laser device. This oxide semiconductor laser device has device characteristics of narrow emission angle and low lasing threshold current, and also has an excellent stability of a propagation mode.
Patent Literature 1: Japanese Patent Application Laid-open No. 2000-299532
Patent Literature 2: Japanese Patent Application Laid-open No. 2005-39107